1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * Copyright 2002-2005, Instant802 Networks, Inc.
4 * Copyright 2005-2006, Devicescape Software, Inc.
5 * Copyright (c) 2006 Jiri Benc <jbenc@suse.cz>
6 * Copyright 2017 Intel Deutschland GmbH
7 * Copyright (C) 2019, 2022-2024 Intel Corporation
8 */
9
10 #include <linux/kernel.h>
11 #include <linux/rtnetlink.h>
12 #include <linux/module.h>
13 #include <linux/slab.h>
14 #include "rate.h"
15 #include "ieee80211_i.h"
16 #include "debugfs.h"
17
18 struct rate_control_alg {
19 struct list_head list;
20 const struct rate_control_ops *ops;
21 };
22
23 static LIST_HEAD(rate_ctrl_algs);
24 static DEFINE_MUTEX(rate_ctrl_mutex);
25
26 static char *ieee80211_default_rc_algo = CONFIG_MAC80211_RC_DEFAULT;
27 module_param(ieee80211_default_rc_algo, charp, 0644);
28 MODULE_PARM_DESC(ieee80211_default_rc_algo,
29 "Default rate control algorithm for mac80211 to use");
30
31 void rate_control_rate_init(struct sta_info *sta)
32 {
33 struct ieee80211_local *local = sta->sdata->local;
34 struct rate_control_ref *ref = sta->rate_ctrl;
35 struct ieee80211_sta *ista = &sta->sta;
36 void *priv_sta = sta->rate_ctrl_priv;
37 struct ieee80211_supported_band *sband;
38 struct ieee80211_chanctx_conf *chanctx_conf;
39
40 ieee80211_sta_init_nss(&sta->deflink);
41
42 if (!ref)
43 return;
44
45 rcu_read_lock();
46
47 chanctx_conf = rcu_dereference(sta->sdata->vif.bss_conf.chanctx_conf);
48 if (WARN_ON(!chanctx_conf)) {
49 rcu_read_unlock();
50 return;
51 }
52
53 sband = local->hw.wiphy->bands[chanctx_conf->def.chan->band];
54
55 /* TODO: check for minstrel_s1g ? */
56 if (sband->band == NL80211_BAND_S1GHZ) {
57 ieee80211_s1g_sta_rate_init(sta);
58 rcu_read_unlock();
59 return;
60 }
61
62 spin_lock_bh(&sta->rate_ctrl_lock);
63 ref->ops->rate_init(ref->priv, sband, &chanctx_conf->def, ista,
64 priv_sta);
65 spin_unlock_bh(&sta->rate_ctrl_lock);
66 rcu_read_unlock();
67 set_sta_flag(sta, WLAN_STA_RATE_CONTROL);
68 }
69
70 void rate_control_tx_status(struct ieee80211_local *local,
71 struct ieee80211_tx_status *st)
72 {
73 struct rate_control_ref *ref = local->rate_ctrl;
74 struct sta_info *sta = container_of(st->sta, struct sta_info, sta);
75 void *priv_sta = sta->rate_ctrl_priv;
76 struct ieee80211_supported_band *sband;
77
78 if (!ref || !test_sta_flag(sta, WLAN_STA_RATE_CONTROL))
79 return;
80
81 sband = local->hw.wiphy->bands[st->info->band];
82
83 spin_lock_bh(&sta->rate_ctrl_lock);
84 if (ref->ops->tx_status_ext)
85 ref->ops->tx_status_ext(ref->priv, sband, priv_sta, st);
86 else if (st->skb)
87 ref->ops->tx_status(ref->priv, sband, st->sta, priv_sta, st->skb);
88 else
89 WARN_ON_ONCE(1);
90
91 spin_unlock_bh(&sta->rate_ctrl_lock);
92 }
93
94 void rate_control_rate_update(struct ieee80211_local *local,
95 struct ieee80211_supported_band *sband,
96 struct sta_info *sta, unsigned int link_id,
97 u32 changed)
98 {
99 struct rate_control_ref *ref = local->rate_ctrl;
100 struct ieee80211_sta *ista = &sta->sta;
101 void *priv_sta = sta->rate_ctrl_priv;
102 struct ieee80211_chanctx_conf *chanctx_conf;
103
104 WARN_ON(link_id != 0);
105
106 if (ref && ref->ops->rate_update) {
107 rcu_read_lock();
108
109 chanctx_conf = rcu_dereference(sta->sdata->vif.bss_conf.chanctx_conf);
110 if (WARN_ON(!chanctx_conf)) {
111 rcu_read_unlock();
112 return;
113 }
114
115 spin_lock_bh(&sta->rate_ctrl_lock);
116 ref->ops->rate_update(ref->priv, sband, &chanctx_conf->def,
117 ista, priv_sta, changed);
118 spin_unlock_bh(&sta->rate_ctrl_lock);
119 rcu_read_unlock();
120 }
121
122 if (sta->uploaded)
123 drv_sta_rc_update(local, sta->sdata, &sta->sta, changed);
124 }
125
126 int ieee80211_rate_control_register(const struct rate_control_ops *ops)
127 {
128 struct rate_control_alg *alg;
129
130 if (!ops->name)
131 return -EINVAL;
132
133 mutex_lock(&rate_ctrl_mutex);
134 list_for_each_entry(alg, &rate_ctrl_algs, list) {
135 if (!strcmp(alg->ops->name, ops->name)) {
136 /* don't register an algorithm twice */
137 WARN_ON(1);
138 mutex_unlock(&rate_ctrl_mutex);
139 return -EALREADY;
140 }
141 }
142
143 alg = kzalloc(sizeof(*alg), GFP_KERNEL);
144 if (alg == NULL) {
145 mutex_unlock(&rate_ctrl_mutex);
146 return -ENOMEM;
147 }
148 alg->ops = ops;
149
150 list_add_tail(&alg->list, &rate_ctrl_algs);
151 mutex_unlock(&rate_ctrl_mutex);
152
153 return 0;
154 }
155 EXPORT_SYMBOL(ieee80211_rate_control_register);
156
157 void ieee80211_rate_control_unregister(const struct rate_control_ops *ops)
158 {
159 struct rate_control_alg *alg;
160
161 mutex_lock(&rate_ctrl_mutex);
162 list_for_each_entry(alg, &rate_ctrl_algs, list) {
163 if (alg->ops == ops) {
164 list_del(&alg->list);
165 kfree(alg);
166 break;
167 }
168 }
169 mutex_unlock(&rate_ctrl_mutex);
170 }
171 EXPORT_SYMBOL(ieee80211_rate_control_unregister);
172
173 static const struct rate_control_ops *
174 ieee80211_try_rate_control_ops_get(const char *name)
175 {
176 struct rate_control_alg *alg;
177 const struct rate_control_ops *ops = NULL;
178
179 if (!name)
180 return NULL;
181
182 mutex_lock(&rate_ctrl_mutex);
183 list_for_each_entry(alg, &rate_ctrl_algs, list) {
184 if (!strcmp(alg->ops->name, name)) {
185 ops = alg->ops;
186 break;
187 }
188 }
189 mutex_unlock(&rate_ctrl_mutex);
190 return ops;
191 }
192
193 /* Get the rate control algorithm. */
194 static const struct rate_control_ops *
195 ieee80211_rate_control_ops_get(const char *name)
196 {
197 const struct rate_control_ops *ops;
198 const char *alg_name;
199
200 kernel_param_lock(THIS_MODULE);
201 if (!name)
202 alg_name = ieee80211_default_rc_algo;
203 else
204 alg_name = name;
205
206 ops = ieee80211_try_rate_control_ops_get(alg_name);
207 if (!ops && name)
208 /* try default if specific alg requested but not found */
209 ops = ieee80211_try_rate_control_ops_get(ieee80211_default_rc_algo);
210
211 /* Note: check for > 0 is intentional to avoid clang warning */
212 if (!ops && (strlen(CONFIG_MAC80211_RC_DEFAULT) > 0))
213 /* try built-in one if specific alg requested but not found */
214 ops = ieee80211_try_rate_control_ops_get(CONFIG_MAC80211_RC_DEFAULT);
215
216 kernel_param_unlock(THIS_MODULE);
217
218 return ops;
219 }
220
221 #ifdef CONFIG_MAC80211_DEBUGFS
222 static ssize_t rcname_read(struct file *file, char __user *userbuf,
223 size_t count, loff_t *ppos)
224 {
225 struct rate_control_ref *ref = file->private_data;
226 int len = strlen(ref->ops->name);
227
228 return simple_read_from_buffer(userbuf, count, ppos,
229 ref->ops->name, len);
230 }
231
232 const struct file_operations rcname_ops = {
233 .read = rcname_read,
234 .open = simple_open,
235 .llseek = default_llseek,
236 };
237 #endif
238
239 static struct rate_control_ref *
240 rate_control_alloc(const char *name, struct ieee80211_local *local)
241 {
242 struct rate_control_ref *ref;
243
244 ref = kmalloc(sizeof(struct rate_control_ref), GFP_KERNEL);
245 if (!ref)
246 return NULL;
247 ref->ops = ieee80211_rate_control_ops_get(name);
248 if (!ref->ops)
249 goto free;
250
251 ref->priv = ref->ops->alloc(&local->hw);
252 if (!ref->priv)
253 goto free;
254 return ref;
255
256 free:
257 kfree(ref);
258 return NULL;
259 }
260
261 static void rate_control_free(struct ieee80211_local *local,
262 struct rate_control_ref *ctrl_ref)
263 {
264 ctrl_ref->ops->free(ctrl_ref->priv);
265
266 #ifdef CONFIG_MAC80211_DEBUGFS
267 debugfs_remove_recursive(local->debugfs.rcdir);
268 local->debugfs.rcdir = NULL;
269 #endif
270
271 kfree(ctrl_ref);
272 }
273
274 void ieee80211_check_rate_mask(struct ieee80211_link_data *link)
275 {
276 struct ieee80211_sub_if_data *sdata = link->sdata;
277 struct ieee80211_local *local = sdata->local;
278 struct ieee80211_supported_band *sband;
279 u32 user_mask, basic_rates = link->conf->basic_rates;
280 enum nl80211_band band;
281
282 if (WARN_ON(!link->conf->chanreq.oper.chan))
283 return;
284
285 band = link->conf->chanreq.oper.chan->band;
286 if (band == NL80211_BAND_S1GHZ) {
287 /* TODO */
288 return;
289 }
290
291 if (WARN_ON_ONCE(!basic_rates))
292 return;
293
294 user_mask = sdata->rc_rateidx_mask[band];
295 sband = local->hw.wiphy->bands[band];
296
297 if (user_mask & basic_rates)
298 return;
299
300 sdata_dbg(sdata,
301 "no overlap between basic rates (0x%x) and user mask (0x%x on band %d) - clearing the latter",
302 basic_rates, user_mask, band);
303 sdata->rc_rateidx_mask[band] = (1 << sband->n_bitrates) - 1;
304 }
305
306 static bool rc_no_data_or_no_ack_use_min(struct ieee80211_tx_rate_control *txrc)
307 {
308 struct sk_buff *skb = txrc->skb;
309 struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
310
311 return (info->flags & (IEEE80211_TX_CTL_NO_ACK |
312 IEEE80211_TX_CTL_USE_MINRATE)) ||
313 !ieee80211_is_tx_data(skb);
314 }
315
316 static void rc_send_low_basicrate(struct ieee80211_tx_rate *rate,
317 u32 basic_rates,
318 struct ieee80211_supported_band *sband)
319 {
320 u8 i;
321
322 if (sband->band == NL80211_BAND_S1GHZ) {
323 /* TODO */
324 rate->flags |= IEEE80211_TX_RC_S1G_MCS;
325 rate->idx = 0;
326 return;
327 }
328
329 if (basic_rates == 0)
330 return; /* assume basic rates unknown and accept rate */
331 if (rate->idx < 0)
332 return;
333 if (basic_rates & (1 << rate->idx))
334 return; /* selected rate is a basic rate */
335
336 for (i = rate->idx + 1; i <= sband->n_bitrates; i++) {
337 if (basic_rates & (1 << i)) {
338 rate->idx = i;
339 return;
340 }
341 }
342
343 /* could not find a basic rate; use original selection */
344 }
345
346 static void __rate_control_send_low(struct ieee80211_hw *hw,
347 struct ieee80211_supported_band *sband,
348 struct ieee80211_sta *sta,
349 struct ieee80211_tx_info *info,
350 u32 rate_mask)
351 {
352 int i;
353 u32 rate_flags =
354 ieee80211_chandef_rate_flags(&hw->conf.chandef);
355
356 if (sband->band == NL80211_BAND_S1GHZ) {
357 info->control.rates[0].flags |= IEEE80211_TX_RC_S1G_MCS;
358 info->control.rates[0].idx = 0;
359 return;
360 }
361
362 if ((sband->band == NL80211_BAND_2GHZ) &&
363 (info->flags & IEEE80211_TX_CTL_NO_CCK_RATE))
364 rate_flags |= IEEE80211_RATE_ERP_G;
365
366 info->control.rates[0].idx = 0;
367 for (i = 0; i < sband->n_bitrates; i++) {
368 if (!(rate_mask & BIT(i)))
369 continue;
370
371 if ((rate_flags & sband->bitrates[i].flags) != rate_flags)
372 continue;
373
374 if (!rate_supported(sta, sband->band, i))
375 continue;
376
377 info->control.rates[0].idx = i;
378 break;
379 }
380 WARN_ONCE(i == sband->n_bitrates,
381 "no supported rates for sta %pM (0x%x, band %d) in rate_mask 0x%x with flags 0x%x\n",
382 sta ? sta->addr : NULL,
383 sta ? sta->deflink.supp_rates[sband->band] : -1,
384 sband->band,
385 rate_mask, rate_flags);
386
387 info->control.rates[0].count =
388 (info->flags & IEEE80211_TX_CTL_NO_ACK) ?
389 1 : hw->max_rate_tries;
390
391 info->control.skip_table = 1;
392 }
393
394
395 static bool rate_control_send_low(struct ieee80211_sta *pubsta,
396 struct ieee80211_tx_rate_control *txrc)
397 {
398 struct ieee80211_tx_info *info = IEEE80211_SKB_CB(txrc->skb);
399 struct ieee80211_supported_band *sband = txrc->sband;
400 struct sta_info *sta;
401 int mcast_rate;
402 bool use_basicrate = false;
403
404 if (!pubsta || rc_no_data_or_no_ack_use_min(txrc)) {
405 __rate_control_send_low(txrc->hw, sband, pubsta, info,
406 txrc->rate_idx_mask);
407
408 if (!pubsta && txrc->bss) {
409 mcast_rate = txrc->bss_conf->mcast_rate[sband->band];
410 if (mcast_rate > 0) {
411 info->control.rates[0].idx = mcast_rate - 1;
412 return true;
413 }
414 use_basicrate = true;
415 } else if (pubsta) {
416 sta = container_of(pubsta, struct sta_info, sta);
417 if (ieee80211_vif_is_mesh(&sta->sdata->vif))
418 use_basicrate = true;
419 }
420
421 if (use_basicrate)
422 rc_send_low_basicrate(&info->control.rates[0],
423 txrc->bss_conf->basic_rates,
424 sband);
425
426 return true;
427 }
428 return false;
429 }
430
431 static bool rate_idx_match_legacy_mask(s8 *rate_idx, int n_bitrates, u32 mask)
432 {
433 int j;
434
435 /* See whether the selected rate or anything below it is allowed. */
436 for (j = *rate_idx; j >= 0; j--) {
437 if (mask & (1 << j)) {
438 /* Okay, found a suitable rate. Use it. */
439 *rate_idx = j;
440 return true;
441 }
442 }
443
444 /* Try to find a higher rate that would be allowed */
445 for (j = *rate_idx + 1; j < n_bitrates; j++) {
446 if (mask & (1 << j)) {
447 /* Okay, found a suitable rate. Use it. */
448 *rate_idx = j;
449 return true;
450 }
451 }
452 return false;
453 }
454
455 static bool rate_idx_match_mcs_mask(s8 *rate_idx, u8 *mcs_mask)
456 {
457 int i, j;
458 int ridx, rbit;
459
460 ridx = *rate_idx / 8;
461 rbit = *rate_idx % 8;
462
463 /* sanity check */
464 if (ridx < 0 || ridx >= IEEE80211_HT_MCS_MASK_LEN)
465 return false;
466
467 /* See whether the selected rate or anything below it is allowed. */
468 for (i = ridx; i >= 0; i--) {
469 for (j = rbit; j >= 0; j--)
470 if (mcs_mask[i] & BIT(j)) {
471 *rate_idx = i * 8 + j;
472 return true;
473 }
474 rbit = 7;
475 }
476
477 /* Try to find a higher rate that would be allowed */
478 ridx = (*rate_idx + 1) / 8;
479 rbit = (*rate_idx + 1) % 8;
480
481 for (i = ridx; i < IEEE80211_HT_MCS_MASK_LEN; i++) {
482 for (j = rbit; j < 8; j++)
483 if (mcs_mask[i] & BIT(j)) {
484 *rate_idx = i * 8 + j;
485 return true;
486 }
487 rbit = 0;
488 }
489 return false;
490 }
491
492 static bool rate_idx_match_vht_mcs_mask(s8 *rate_idx, u16 *vht_mask)
493 {
494 int i, j;
495 int ridx, rbit;
496
497 ridx = *rate_idx >> 4;
498 rbit = *rate_idx & 0xf;
499
500 if (ridx < 0 || ridx >= NL80211_VHT_NSS_MAX)
501 return false;
502
503 /* See whether the selected rate or anything below it is allowed. */
504 for (i = ridx; i >= 0; i--) {
505 for (j = rbit; j >= 0; j--) {
506 if (vht_mask[i] & BIT(j)) {
507 *rate_idx = (i << 4) | j;
508 return true;
509 }
510 }
511 rbit = 15;
512 }
513
514 /* Try to find a higher rate that would be allowed */
515 ridx = (*rate_idx + 1) >> 4;
516 rbit = (*rate_idx + 1) & 0xf;
517
518 for (i = ridx; i < NL80211_VHT_NSS_MAX; i++) {
519 for (j = rbit; j < 16; j++) {
520 if (vht_mask[i] & BIT(j)) {
521 *rate_idx = (i << 4) | j;
522 return true;
523 }
524 }
525 rbit = 0;
526 }
527 return false;
528 }
529
530 static void rate_idx_match_mask(s8 *rate_idx, u16 *rate_flags,
531 struct ieee80211_supported_band *sband,
532 enum nl80211_chan_width chan_width,
533 u32 mask,
534 u8 mcs_mask[IEEE80211_HT_MCS_MASK_LEN],
535 u16 vht_mask[NL80211_VHT_NSS_MAX])
536 {
537 if (*rate_flags & IEEE80211_TX_RC_VHT_MCS) {
538 /* handle VHT rates */
539 if (rate_idx_match_vht_mcs_mask(rate_idx, vht_mask))
540 return;
541
542 *rate_idx = 0;
543 /* keep protection flags */
544 *rate_flags &= (IEEE80211_TX_RC_USE_RTS_CTS |
545 IEEE80211_TX_RC_USE_CTS_PROTECT |
546 IEEE80211_TX_RC_USE_SHORT_PREAMBLE);
547
548 *rate_flags |= IEEE80211_TX_RC_MCS;
549 if (chan_width == NL80211_CHAN_WIDTH_40)
550 *rate_flags |= IEEE80211_TX_RC_40_MHZ_WIDTH;
551
552 if (rate_idx_match_mcs_mask(rate_idx, mcs_mask))
553 return;
554
555 /* also try the legacy rates. */
556 *rate_flags &= ~(IEEE80211_TX_RC_MCS |
557 IEEE80211_TX_RC_40_MHZ_WIDTH);
558 if (rate_idx_match_legacy_mask(rate_idx, sband->n_bitrates,
559 mask))
560 return;
561 } else if (*rate_flags & IEEE80211_TX_RC_MCS) {
562 /* handle HT rates */
563 if (rate_idx_match_mcs_mask(rate_idx, mcs_mask))
564 return;
565
566 /* also try the legacy rates. */
567 *rate_idx = 0;
568 /* keep protection flags */
569 *rate_flags &= (IEEE80211_TX_RC_USE_RTS_CTS |
570 IEEE80211_TX_RC_USE_CTS_PROTECT |
571 IEEE80211_TX_RC_USE_SHORT_PREAMBLE);
572 if (rate_idx_match_legacy_mask(rate_idx, sband->n_bitrates,
573 mask))
574 return;
575 } else {
576 /* handle legacy rates */
577 if (rate_idx_match_legacy_mask(rate_idx, sband->n_bitrates,
578 mask))
579 return;
580
581 /* if HT BSS, and we handle a data frame, also try HT rates */
582 switch (chan_width) {
583 case NL80211_CHAN_WIDTH_20_NOHT:
584 case NL80211_CHAN_WIDTH_5:
585 case NL80211_CHAN_WIDTH_10:
586 return;
587 default:
588 break;
589 }
590
591 *rate_idx = 0;
592 /* keep protection flags */
593 *rate_flags &= (IEEE80211_TX_RC_USE_RTS_CTS |
594 IEEE80211_TX_RC_USE_CTS_PROTECT |
595 IEEE80211_TX_RC_USE_SHORT_PREAMBLE);
596
597 *rate_flags |= IEEE80211_TX_RC_MCS;
598
599 if (chan_width == NL80211_CHAN_WIDTH_40)
600 *rate_flags |= IEEE80211_TX_RC_40_MHZ_WIDTH;
601
602 if (rate_idx_match_mcs_mask(rate_idx, mcs_mask))
603 return;
604 }
605
606 /*
607 * Uh.. No suitable rate exists. This should not really happen with
608 * sane TX rate mask configurations. However, should someone manage to
609 * configure supported rates and TX rate mask in incompatible way,
610 * allow the frame to be transmitted with whatever the rate control
611 * selected.
612 */
613 }
614
615 static void rate_fixup_ratelist(struct ieee80211_vif *vif,
616 struct ieee80211_supported_band *sband,
617 struct ieee80211_tx_info *info,
618 struct ieee80211_tx_rate *rates,
619 int max_rates)
620 {
621 struct ieee80211_rate *rate;
622 bool inval = false;
623 int i;
624
625 /*
626 * Set up the RTS/CTS rate as the fastest basic rate
627 * that is not faster than the data rate unless there
628 * is no basic rate slower than the data rate, in which
629 * case we pick the slowest basic rate
630 *
631 * XXX: Should this check all retry rates?
632 */
633 if (!(rates[0].flags &
634 (IEEE80211_TX_RC_MCS | IEEE80211_TX_RC_VHT_MCS))) {
635 u32 basic_rates = vif->bss_conf.basic_rates;
636 s8 baserate = basic_rates ? ffs(basic_rates) - 1 : 0;
637
638 rate = &sband->bitrates[rates[0].idx];
639
640 for (i = 0; i < sband->n_bitrates; i++) {
641 /* must be a basic rate */
642 if (!(basic_rates & BIT(i)))
643 continue;
644 /* must not be faster than the data rate */
645 if (sband->bitrates[i].bitrate > rate->bitrate)
646 continue;
647 /* maximum */
648 if (sband->bitrates[baserate].bitrate <
649 sband->bitrates[i].bitrate)
650 baserate = i;
651 }
652
653 info->control.rts_cts_rate_idx = baserate;
654 }
655
656 for (i = 0; i < max_rates; i++) {
657 /*
658 * make sure there's no valid rate following
659 * an invalid one, just in case drivers don't
660 * take the API seriously to stop at -1.
661 */
662 if (inval) {
663 rates[i].idx = -1;
664 continue;
665 }
666 if (rates[i].idx < 0) {
667 inval = true;
668 continue;
669 }
670
671 /*
672 * For now assume MCS is already set up correctly, this
673 * needs to be fixed.
674 */
675 if (rates[i].flags & IEEE80211_TX_RC_MCS) {
676 WARN_ON(rates[i].idx > 76);
677
678 if (!(rates[i].flags & IEEE80211_TX_RC_USE_RTS_CTS) &&
679 info->control.use_cts_prot)
680 rates[i].flags |=
681 IEEE80211_TX_RC_USE_CTS_PROTECT;
682 continue;
683 }
684
685 if (rates[i].flags & IEEE80211_TX_RC_VHT_MCS) {
686 WARN_ON(ieee80211_rate_get_vht_mcs(&rates[i]) > 9);
687 continue;
688 }
689
690 /* set up RTS protection if desired */
691 if (info->control.use_rts) {
692 rates[i].flags |= IEEE80211_TX_RC_USE_RTS_CTS;
693 info->control.use_cts_prot = false;
694 }
695
696 /* RC is busted */
697 if (WARN_ON_ONCE(rates[i].idx >= sband->n_bitrates)) {
698 rates[i].idx = -1;
699 continue;
700 }
701
702 rate = &sband->bitrates[rates[i].idx];
703
704 /* set up short preamble */
705 if (info->control.short_preamble &&
706 rate->flags & IEEE80211_RATE_SHORT_PREAMBLE)
707 rates[i].flags |= IEEE80211_TX_RC_USE_SHORT_PREAMBLE;
708
709 /* set up G protection */
710 if (!(rates[i].flags & IEEE80211_TX_RC_USE_RTS_CTS) &&
711 info->control.use_cts_prot &&
712 rate->flags & IEEE80211_RATE_ERP_G)
713 rates[i].flags |= IEEE80211_TX_RC_USE_CTS_PROTECT;
714 }
715 }
716
717
718 static void rate_control_fill_sta_table(struct ieee80211_sta *sta,
719 struct ieee80211_tx_info *info,
720 struct ieee80211_tx_rate *rates,
721 int max_rates)
722 {
723 struct ieee80211_sta_rates *ratetbl = NULL;
724 int i;
725
726 if (sta && !info->control.skip_table)
727 ratetbl = rcu_dereference(sta->rates);
728
729 /* Fill remaining rate slots with data from the sta rate table. */
730 max_rates = min_t(int, max_rates, IEEE80211_TX_RATE_TABLE_SIZE);
731 for (i = 0; i < max_rates; i++) {
732 if (i < ARRAY_SIZE(info->control.rates) &&
733 info->control.rates[i].idx >= 0 &&
734 info->control.rates[i].count) {
735 if (rates != info->control.rates)
736 rates[i] = info->control.rates[i];
737 } else if (ratetbl) {
738 rates[i].idx = ratetbl->rate[i].idx;
739 rates[i].flags = ratetbl->rate[i].flags;
740 if (info->control.use_rts)
741 rates[i].count = ratetbl->rate[i].count_rts;
742 else if (info->control.use_cts_prot)
743 rates[i].count = ratetbl->rate[i].count_cts;
744 else
745 rates[i].count = ratetbl->rate[i].count;
746 } else {
747 rates[i].idx = -1;
748 rates[i].count = 0;
749 }
750
751 if (rates[i].idx < 0 || !rates[i].count)
752 break;
753 }
754 }
755
756 static bool rate_control_cap_mask(struct ieee80211_sub_if_data *sdata,
757 struct ieee80211_supported_band *sband,
758 struct ieee80211_sta *sta, u32 *mask,
759 u8 mcs_mask[IEEE80211_HT_MCS_MASK_LEN],
760 u16 vht_mask[NL80211_VHT_NSS_MAX])
761 {
762 u32 i, flags;
763
764 *mask = sdata->rc_rateidx_mask[sband->band];
765 flags = ieee80211_chandef_rate_flags(&sdata->vif.bss_conf.chanreq.oper);
766 for (i = 0; i < sband->n_bitrates; i++) {
767 if ((flags & sband->bitrates[i].flags) != flags)
768 *mask &= ~BIT(i);
769 }
770
771 if (*mask == (1 << sband->n_bitrates) - 1 &&
772 !sdata->rc_has_mcs_mask[sband->band] &&
773 !sdata->rc_has_vht_mcs_mask[sband->band])
774 return false;
775
776 if (sdata->rc_has_mcs_mask[sband->band])
777 memcpy(mcs_mask, sdata->rc_rateidx_mcs_mask[sband->band],
778 IEEE80211_HT_MCS_MASK_LEN);
779 else
780 memset(mcs_mask, 0xff, IEEE80211_HT_MCS_MASK_LEN);
781
782 if (sdata->rc_has_vht_mcs_mask[sband->band])
783 memcpy(vht_mask, sdata->rc_rateidx_vht_mcs_mask[sband->band],
784 sizeof(u16) * NL80211_VHT_NSS_MAX);
785 else
786 memset(vht_mask, 0xff, sizeof(u16) * NL80211_VHT_NSS_MAX);
787
788 if (sta) {
789 __le16 sta_vht_cap;
790 u16 sta_vht_mask[NL80211_VHT_NSS_MAX];
791
792 /* Filter out rates that the STA does not support */
793 *mask &= sta->deflink.supp_rates[sband->band];
794 for (i = 0; i < IEEE80211_HT_MCS_MASK_LEN; i++)
795 mcs_mask[i] &= sta->deflink.ht_cap.mcs.rx_mask[i];
796
797 sta_vht_cap = sta->deflink.vht_cap.vht_mcs.rx_mcs_map;
798 ieee80211_get_vht_mask_from_cap(sta_vht_cap, sta_vht_mask);
799 for (i = 0; i < NL80211_VHT_NSS_MAX; i++)
800 vht_mask[i] &= sta_vht_mask[i];
801 }
802
803 return true;
804 }
805
806 static void
807 rate_control_apply_mask_ratetbl(struct sta_info *sta,
808 struct ieee80211_supported_band *sband,
809 struct ieee80211_sta_rates *rates)
810 {
811 int i;
812 u32 mask;
813 u8 mcs_mask[IEEE80211_HT_MCS_MASK_LEN];
814 u16 vht_mask[NL80211_VHT_NSS_MAX];
815 enum nl80211_chan_width chan_width;
816
817 if (!rate_control_cap_mask(sta->sdata, sband, &sta->sta, &mask,
818 mcs_mask, vht_mask))
819 return;
820
821 chan_width = sta->sdata->vif.bss_conf.chanreq.oper.width;
822 for (i = 0; i < IEEE80211_TX_RATE_TABLE_SIZE; i++) {
823 if (rates->rate[i].idx < 0)
824 break;
825
826 rate_idx_match_mask(&rates->rate[i].idx, &rates->rate[i].flags,
827 sband, chan_width, mask, mcs_mask,
828 vht_mask);
829 }
830 }
831
832 static void rate_control_apply_mask(struct ieee80211_sub_if_data *sdata,
833 struct ieee80211_sta *sta,
834 struct ieee80211_supported_band *sband,
835 struct ieee80211_tx_rate *rates,
836 int max_rates)
837 {
838 enum nl80211_chan_width chan_width;
839 u8 mcs_mask[IEEE80211_HT_MCS_MASK_LEN];
840 u32 mask;
841 u16 rate_flags, vht_mask[NL80211_VHT_NSS_MAX];
842 int i;
843
844 /*
845 * Try to enforce the rateidx mask the user wanted. skip this if the
846 * default mask (allow all rates) is used to save some processing for
847 * the common case.
848 */
849 if (!rate_control_cap_mask(sdata, sband, sta, &mask, mcs_mask,
850 vht_mask))
851 return;
852
853 /*
854 * Make sure the rate index selected for each TX rate is
855 * included in the configured mask and change the rate indexes
856 * if needed.
857 */
858 chan_width = sdata->vif.bss_conf.chanreq.oper.width;
859 for (i = 0; i < max_rates; i++) {
860 /* Skip invalid rates */
861 if (rates[i].idx < 0)
862 break;
863
864 rate_flags = rates[i].flags;
865 rate_idx_match_mask(&rates[i].idx, &rate_flags, sband,
866 chan_width, mask, mcs_mask, vht_mask);
867 rates[i].flags = rate_flags;
868 }
869 }
870
871 void ieee80211_get_tx_rates(struct ieee80211_vif *vif,
872 struct ieee80211_sta *sta,
873 struct sk_buff *skb,
874 struct ieee80211_tx_rate *dest,
875 int max_rates)
876 {
877 struct ieee80211_sub_if_data *sdata;
878 struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
879 struct ieee80211_supported_band *sband;
880 u32 mask = ~0;
881
882 rate_control_fill_sta_table(sta, info, dest, max_rates);
883
884 if (!vif)
885 return;
886
887 sdata = vif_to_sdata(vif);
888 sband = sdata->local->hw.wiphy->bands[info->band];
889
890 if (ieee80211_is_tx_data(skb))
891 rate_control_apply_mask(sdata, sta, sband, dest, max_rates);
892
893 if (!(info->control.flags & IEEE80211_TX_CTRL_SCAN_TX))
894 mask = sdata->rc_rateidx_mask[info->band];
895
896 if (dest[0].idx < 0)
897 __rate_control_send_low(&sdata->local->hw, sband, sta, info,
898 mask);
899
900 if (sta)
901 rate_fixup_ratelist(vif, sband, info, dest, max_rates);
902 }
903 EXPORT_SYMBOL(ieee80211_get_tx_rates);
904
905 void rate_control_get_rate(struct ieee80211_sub_if_data *sdata,
906 struct sta_info *sta,
907 struct ieee80211_tx_rate_control *txrc)
908 {
909 struct rate_control_ref *ref = sdata->local->rate_ctrl;
910 void *priv_sta = NULL;
911 struct ieee80211_sta *ista = NULL;
912 struct ieee80211_tx_info *info = IEEE80211_SKB_CB(txrc->skb);
913 int i;
914
915 for (i = 0; i < IEEE80211_TX_MAX_RATES; i++) {
916 info->control.rates[i].idx = -1;
917 info->control.rates[i].flags = 0;
918 info->control.rates[i].count = 0;
919 }
920
921 if (rate_control_send_low(sta ? &sta->sta : NULL, txrc))
922 return;
923
924 if (ieee80211_hw_check(&sdata->local->hw, HAS_RATE_CONTROL))
925 return;
926
927 if (sta && test_sta_flag(sta, WLAN_STA_RATE_CONTROL)) {
928 ista = &sta->sta;
929 priv_sta = sta->rate_ctrl_priv;
930 }
931
932 if (ista) {
933 spin_lock_bh(&sta->rate_ctrl_lock);
934 ref->ops->get_rate(ref->priv, ista, priv_sta, txrc);
935 spin_unlock_bh(&sta->rate_ctrl_lock);
936 } else {
937 rate_control_send_low(NULL, txrc);
938 }
939
940 if (ieee80211_hw_check(&sdata->local->hw, SUPPORTS_RC_TABLE))
941 return;
942
943 ieee80211_get_tx_rates(&sdata->vif, ista, txrc->skb,
944 info->control.rates,
945 ARRAY_SIZE(info->control.rates));
946 }
947
948 int rate_control_set_rates(struct ieee80211_hw *hw,
949 struct ieee80211_sta *pubsta,
950 struct ieee80211_sta_rates *rates)
951 {
952 struct sta_info *sta = container_of(pubsta, struct sta_info, sta);
953 struct ieee80211_sta_rates *old;
954 struct ieee80211_supported_band *sband;
955
956 sband = ieee80211_get_sband(sta->sdata);
957 if (!sband)
958 return -EINVAL;
959 rate_control_apply_mask_ratetbl(sta, sband, rates);
960 /*
961 * mac80211 guarantees that this function will not be called
962 * concurrently, so the following RCU access is safe, even without
963 * extra locking. This can not be checked easily, so we just set
964 * the condition to true.
965 */
966 old = rcu_dereference_protected(pubsta->rates, true);
967 rcu_assign_pointer(pubsta->rates, rates);
968 if (old)
969 kfree_rcu(old, rcu_head);
970
971 if (sta->uploaded)
972 drv_sta_rate_tbl_update(hw_to_local(hw), sta->sdata, pubsta);
973
974 ieee80211_sta_set_expected_throughput(pubsta, sta_get_expected_throughput(sta));
975
976 return 0;
977 }
978 EXPORT_SYMBOL(rate_control_set_rates);
979
980 int ieee80211_init_rate_ctrl_alg(struct ieee80211_local *local,
981 const char *name)
982 {
983 struct rate_control_ref *ref;
984
985 ASSERT_RTNL();
986
987 if (local->open_count)
988 return -EBUSY;
989
990 if (ieee80211_hw_check(&local->hw, HAS_RATE_CONTROL)) {
991 if (WARN_ON(!local->ops->set_rts_threshold))
992 return -EINVAL;
993 return 0;
994 }
995
996 ref = rate_control_alloc(name, local);
997 if (!ref) {
998 wiphy_warn(local->hw.wiphy,
999 "Failed to select rate control algorithm\n");
1000 return -ENOENT;
1001 }
1002
1003 WARN_ON(local->rate_ctrl);
1004 local->rate_ctrl = ref;
1005
1006 wiphy_debug(local->hw.wiphy, "Selected rate control algorithm '%s'\n",
1007 ref->ops->name);
1008
1009 return 0;
1010 }
1011
1012 void rate_control_deinitialize(struct ieee80211_local *local)
1013 {
1014 struct rate_control_ref *ref;
1015
1016 ref = local->rate_ctrl;
1017
1018 if (!ref)
1019 return;
1020
1021 local->rate_ctrl = NULL;
1022 rate_control_free(local, ref);
1023 }
1024
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